import Map from '../src/ol/Map.js';
import View from '../src/ol/View.js';
import WKT from '../src/ol/format/WKT.js';
import {Tile as TileLayer, Vector as VectorLayer} from '../src/ol/layer.js';
import {OSM, Vector as VectorSource} from '../src/ol/source.js';

const raster = new TileLayer({
  source: new OSM()
});

const format = new WKT();
const feature = format.readFeature(
  'POLYGON((10.689697265625 -25.0927734375, 34.595947265625 ' +
        '-20.1708984375, 38.814697265625 -35.6396484375, 13.502197265625 ' +
        '-39.1552734375, 10.689697265625 -25.0927734375))');
feature.getGeometry().transform('EPSG:4326', 'EPSG:3857');

const vector = new VectorLayer({
  source: new VectorSource({
    features: [feature]
  }),
  opacity: 0.5
});


const map = new Map({
  layers: [raster, vector],
  target: 'map',
  view: new View({
    center: [0, 0],
    zoom: 2
  })
});


const dims = {
  a0: [1189, 841],
  a1: [841, 594],
  a2: [594, 420],
  a3: [420, 297],
  a4: [297, 210],
  a5: [210, 148]
};


const exportButton = document.getElementById('export-pdf');

exportButton.addEventListener('click', function() {

  exportButton.disabled = true;
  document.body.style.cursor = 'progress';

  const format = document.getElementById('format').value;
  const resolution = document.getElementById('resolution').value;
  const dim = dims[format];
  const width = Math.round(dim[0] * resolution / 25.4);
  const height = Math.round(dim[1] * resolution / 25.4);
  const size = map.getSize();
  const viewResolution = map.getView().getResolution();

  map.once('rendercomplete', function() {
    const mapCanvas = document.createElement('canvas');
    mapCanvas.width = width;
    mapCanvas.height = height;
    const mapContext = mapCanvas.getContext('2d');
    Array.prototype.forEach.call(document.querySelectorAll('.ol-layer canvas'), function(canvas) {
      if (canvas.width > 0) {
        const opacity = canvas.parentNode.style.opacity;
        mapContext.globalAlpha = opacity === '' ? 1 : Number(opacity);
        const transform = canvas.style.transform;
        // Get the transform parameters from the style's transform matrix
        const matrix = transform.match(/^matrix\(([^\(]*)\)$/)[1].split(',').map(Number);
        // Apply the transform to the export map context
        CanvasRenderingContext2D.prototype.setTransform.apply(mapContext, matrix);
        mapContext.drawImage(canvas, 0, 0);
      }
    });
    const pdf = new jsPDF('landscape', undefined, format);
    pdf.addImage(mapCanvas.toDataURL('image/jpeg'), 'JPEG', 0, 0, dim[0], dim[1]);
    pdf.save('map.pdf');
    // Reset original map size
    map.setSize(size);
    map.getView().setResolution(viewResolution);
    exportButton.disabled = false;
    document.body.style.cursor = 'auto';
  });

  // Set print size
  const printSize = [width, height];
  map.setSize(printSize);
  const scaling = Math.min(width / size[0], height / size[1]);
  map.getView().setResolution(viewResolution / scaling);

}, false);
